1. Field of the Invention
The present invention relates to a pot-shaped grinding wheel including a circular grinding region provided with a plurality of segment-like grinding members, a circular seat region coaxial with and axially spaced from the grinding region, a transition region extending between an inner contour of the grinding region and an outer contour of the seat region, and at least two bores extending parallel to an axis of the grinding wheel.
2. Description of the Prior Art
For grinding outer surfaces of mineral constructional components and constructional components provided with a coating layer, a pot-shaped grinding wheel such as disclosed, e.g., in European Publication EP 0 535 431, is used. The grinding wheel is mounted on an manual angle grinder which, as a rule, is connected with a suction system including a suction hood and a suction device. The pot-shaped grinding wheel is particularly used for eliminating unevenness on stones and coated concrete surfaces and for finishing of facades.
During grinding of a surface, the grinding wheel is displaced along the surface in such a manner that at least a portion of the grinding member, which is located remotely from the grinding wheel seat region, is removed, together with the material of the constructional component. These materials, together with the sand dust, is removed through the bores in the grinding wheel by the suction system from the work region. The bores, which are provided in the grinding wheel, are so arranged that each bore lies partially in the grinding region and partially in the transition region. Because of the conical shape of transition region, the bores open not only into side surface of the grinding region, which is remote from the seat region, but also into a free space which lies between the seat and grinding region and which surrounds the transition region. Therefore, upon actuation of the suction system, first, the air from this free space should be aspirated until a partial vacuum is formed between the grinding region and the ground surface. This presents, in particular, an inconvenience for the operator because the creation of the partial vacuum always delays the start of the grinder and, therefore, the suction of the waste material and of the sand dust cannot be effected at the very beginning of the grinding process. A further drawback of the known grinding wheel consists in that a suction nipple of the suction hood can be superimposed only with one bore. Therefore, the necessary, for suction, vacuum is always provided only through a bore with a superimposed hood nipple. Because the remaining bores form in the transition region passages through which air can penetrate into the free space, it is practically impossible to form a necessary vacuum in the free space, which surrounds the transition region, and between the grinding region and the ground surface of the constructional component.
An object of the present invention is a grinding wheel, which would have a simple construction and could be economically produced and which would insure a rapid a reliable aspiration of the removable material and the sand dust from the work region. The grinding wheel should insure a good grinding performance, good quality of the ground surface of the constructional component, and good cooling of the grinding members. The grinding wheel should not generate any vibrations and should prevent accumulation of the removable material and the sand dust between the grinding members. Further, the construction of the grinding wheel should provide for rapid creation of the necessary vacuum between the grinding region and the surface of a constructional component.